Ahmedabad is a large, rapidly growing city in Gujarat, India, where summer temperatures regularly exceed 40?C. The Ahmedabad Municipal Corporation (AMC) is very concerned about citizens' vulnerability to heat as the climate changes and eager both to learn more about particularly vulnerable populations and to initiate informed public health adaptation efforts. Relatively little is known about heat vulnerability in this arid region, though this consortium of investigators and AMC have already done a preliminary household vulnerability survey. This work has begun to shed light on public perceptions of health, illness, and risk factors, but the true burden of heat-related illness remains unknown. The goal of this proposal is to explore the heat illness burden, vulnerability factors, and response options in Ahmedabad in order to facilitate AMC's adaptation efforts. The proposed project will assess the burden of heat illness via several methods, including a prospective cohort study using an existing community health worker outreach program; assess capacity in the public health and health care delivery sectors; and build relationships between the health sector and the meteorological services sector to improve heat watch warning activities. The project addresses the following specific aims: SA1: To assess the burden of heat illness in Ahmedabad using retrospective and prospective methods and building on existing outreach and surveillance infrastructure, with the aims of developing a syndromic surveillance program; SA2: To assess and build adaptive capacity in Ahmedabad's public health and health care delivery systems through retrospective analyses of the medical management of patients with heat illness, needs assessment with city and public health officials, and training of public health and health care workers on preventing, recognizing, and treating heat illness; and SA3: To work with AMC and the Gujarati Meteorological Department to develop and calibrate a heat watch and warning system for the AMC, using response functions from SA1 and probabilistic ensemble temperature forecasts for the region. We have assembled a consortium of US and Indian scientists with expertise in environmental epidemiology, vulnerability assessment, medicine, public health and health system administration, climate science, and early warning system development. The proposed work includes extensive capacity building for Indian environmental health scientists, public health workers, and health care staff.